Power drive apparatus

1. A power drive apparatus comprising, a main circuit board including an input terminal block for connection to power-source wires mounted on a major surface of said main circuit board; a power module including a converter unit having diodes and an inverter unit having switching devices and diodes, the power module, mounted on the other major surface of said main circuit board, being for converting and outputting electric power supplied through said input terminal block; a heat-dissipating plate, connected with said power module in contact with a surface of said power module opposite to said main circuit board, for dissipating heat generated by said power module; and a filter module including a filter substrate provided with a filter circuit, and being disposed in the middle of an interconnecting path between said input terminal block and an input section of said converter unit, for suppressing the transmission of noise generated by said switching devices to a power source side, wherein said heat-dissipating plate provides therein a concave space, and said filter module is received in said concave space and is detachably mounted on said heat-dissipating plate.

2. The power drive apparatus according to claim 1, wherein said heat-dissipating plate also serves as a grounding conductor, and said filter module is fixed to said heat-dissipating plate by conductive screws passing through a grounding pattern provided on said filter substrate so that said conductive screws are electrically connected to the grounding pattern.

3. The power drive apparatus according to claim 1, wherein said concave space is formed in said heat-dissipating plate so as to have an aperture toward a side opposite to said main circuit board side; a through-hole is formed in said heat-dissipating plate so that said main circuit board side and said concave space are communicated with each other; an interconnecting path between said input terminal block of said main circuit board and the input section of said converter unit is cut in the middle; a plurality of switching terminals electrically connected to each edge of cut portions of said interconnecting path extend in the through-hole from said main circuit board, the plurality of switching terminals being electrically connected through wires to the input terminals and output terminals of said filter circuit, respectively; a plurality of receptor terminals are provided in said filter module, the receptor terminals being capable of coupling with the plurality of switching terminals; and the plurality of receptor terminals are coupled with the plurality of switching terminals, respectively, and said filter circuit is thereby provided in the middle of the interconnecting path between said input terminal block and the input section of said converter unit, when said filter module is received in said concave space and is fixed to said heat-dissipating plate by said screws through the aperture of said concave space formed toward a side thereof opposite to said main circuit board side.

4. The power drive apparatus according to claim 3, further comprising a shortcut board for connecting edges of the cut portions of the interconnecting path to each other by being coupled with the plurality of switching terminals extending in the through-hole from said main circuit board, when said filter module is removed.